#include<stdio.h>
int main()
{
	double grade;
	char level;
	printf("Please enter the student's grade.\n");
	scanf("%lf",&grade);
	if(grade>100||grade<0)
	{
		printf("Invalid grade.\n");
		return 0;
	}
	else if(grade>=90)
		level='A';
	else if(grade>=80)
		level='B';
	else if(grade>=70)
		level='C';
	else if(grade>=60)
		level='D';
	else
		level='E';
	printf("The level is %c",level);
	return 0;
}
